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Reduced quality of MODIS-Aqua data from 2014 onwards

The version 2 dataset extended the time series to the end of 2013 using just MODIS-Aqua from the end of MERIS onwards. However, the project decided to omit the 2014 MODIS-Aqua data because of concerns over its quality, and hence ability to consider it within a climate quality dataset. A presented figure (Bryan Franz, NASA) showed a sharp decline in the Chlorophyll-a values related to 2014 radiometry shifting (up in blue, down in green). The aim was to wait for NASA to undertake a MODIS reprocessing, which would correct for the decay.

For our version 3 dataset we've been able to extend the time series to the end of 2015 by bringing in VIIRS, with reprocessed R2014 MODIS-Aqua extended to the end of 2015. NASA have since issued reprocessed R2014.0.1 MODIS-Aqua data, and so a version 3.0.1 will be issued. However, the quality of the MODIS-Aqua 2014-15 data remains a concern because of the recurrent problems that NASA has been facing.